A light emitting device using an element represented by an LED (Light Emitting Diode) and the like has recently been used in a variety of applications since having advantages of low power consumption, a small size, high luminance and a long lifetime. In particular, attention is being focused on its application to an illumination device that is replaced for an incandescent lamp and the like with large power consumption.
Generally, making the element such as the LED emit white light is difficult, differently from the incandescent lamp. For this reason, the light emitting device using such an element further includes a phosphor, which absorbs light emitted by the element and outputs fluorescent light, and the device emits white light by mixture of the light emitted by the element and the light outputted by the phosphor. For example, there has already been widespread a light emitting device including an LED that emits blue light and a phosphor that outputs yellow fluorescent light.
However, the white (mixed color of blue and yellow) light emitted by the above light emitting device has a smaller red component (is cool-color light) as compared with the white (white generated by radiation and close to natural light) light outputted by the incandescent lamp and the like. For this reason, it is difficult to make such a light emitting device emit white light which is warm-color light required for example for a household illumination device and the like.
Therefore, for example in Patent Document 1, there is provided a light emitting device where an LED that emits blue light and a phosphor that outputs yellow fluorescent light are further added with a phosphor that outputs red fluorescent light, to emit white light replenished with a red component.